That does not make much sense and will cause a lot of confusion. If they want to have the update only for CC fine, but why not naming it ACR CC instead of 8.5? I would be expecting a LR 5.5 following that notice. Additionally, what about those clients who have LR under the CC licensing and use LR for DAM? no more pairing of LR and PS? then please give us a LR CC version.
It makes sense if you understand the fundamental differences between perpetual vs subscription and what Adobe can and can't add to upgrades vs updates. ACR is part of Photoshop CC and as such can get new feature upgrades. LR is still a perpetual licensed product and as such can not get new feature upgrades between major versions.
So, ACR in CC can get new feature upgrades while LR can not.
Ignore for the moment that LR is part of the CC product lineup (if bought as the photographers bundle or the full CC bundle) because LR is still controlled by it's basis as a perpetual license product.
So, ACR for Photoshop CC can get incremental feature upgrades while LR can not.
And yes, this means that ACR & LR will no longer have 1:1 feature parity. We've already seen this with ACR 8.4.
LR won't get the new features in ACR 8.5 till the next major LR upgrade–LR 6.